Frost Dates for 60133 — Hanover Park, Illinois

Half of springs at Streamwood, IL see their last 32°F night by April 30; only one in ten is past it by April 17, and one in ten still has one after May 16. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 10 20%, and after May 16 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 22% of the 158 Illinois stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 13 in half of years, as early as September 29 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 11 days later, around October 24; in spring the one-in-ten date for 28°F is May 3, 13 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, shorter than at 96% of the 158 Illinois stations; it reaches 182 days one year in ten and falls short of 143 one year in ten. On average 153 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about May 12, and return around October 4. Severe cold of 16°F or below comes every winter, usually between November 24 and March 19.

July is the warmest month at Streamwood, IL, averaging 87°F by day and 61°F at night; January is the coldest at 32°F and 14°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 50% of years.

Warmth for growing adds up to 3,102 growing degree days a year (base 50°F), fewer than at 79% of the 158 Illinois stations. 34% of them (1,040) have built up by the end of June, and July adds the most, 749. Precipitation totals 38.0 inches a year, most in May (4.7") and least in February (1.7"); May to September bring 55% of it.

The nearest other station, West Chicago Dupage Airport, IL, 7 miles southwest of Hanover Park, has a last frost 5 days earlier (April 25), a first frost 6 days later (October 19), a season 11 days longer.

The first measurable snow (0.1 inch or more) in Hanover Park usually arrives around November 17, and the last of the season around April 6. Those are the middle dates across the winters of 1991–2020 at Streamwood, IL, 3.5 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 24 days after the last snow.

ZIP 60133 is 4 miles from Streamwood, IL, which stands at 819 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 60103 (Bartlett). The 2023 USDA Plant Hardiness Zone Map lists ZIP 60133 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.